Gear ratio effect on stopping/skidding

what other ways are there to stop brakeless

[serious reply] The only way to stop when riding brakeless is by using your legs. This broadly speaking breaks down in to three categories:

1) Resisting. This is where your legs resist the motion of the cranks, pushing down as they push up and pulling up as they go down. The more aggressively you resist the faster you slow. This is live feathering your rear brake on a normal bike. Great for slowing down or controlling your speed, but it isn't going to stop you quickly when you are going at speed. However this is probably the most used method of braking on a fixed gear bicycle, with or without a front brake.

2) Skidding. This is where you 'lock' your legs (I don't like this term, as I don't feel its truly accurate), thus locking the rear wheel, causing a skid. With your weight thrown forward this skidding can last for a long time, and is considered by many to be a type of trick. Indeed there are many a skidding competition and variations. With your weight further back the skid is shorter, and can stop you reasonably quickly,and I am not convinced it can ever stop you as quickly as a front brake, but does encourage you to ride more defensively and pre-empt what is going to happen. In any case a short sharp skid is probably the most instantaneous stop you can get when riding brakeless. Others have already detailed how to do it, but for completeness sake you basicaly push back on the cranks when one arm is in the 4 O'clock position, whilst simultaneously pulling up on the other crank when its at 10 O'clock (or 3 and 9 respectively if you prefer, everyone is different). Moving your weight forward helps, as you want to unweight the rear wheel to help initiate the skid on higher gears. Its also worth noting that the higher your gearing the harder it is to skid, the lower the gearing the easier. Anything under 60GI is super super easy to skid, even when sitting down (at least thats my experiences). Oh and skidding is the fastest way to go through your tyre.
EDIT: I should of mentioned that when skidding if you flick the back end out to one side you can stop over less ground, as the momentum is dissipated by the rear wheel moving out to the side rather then forward, if you get what I mean.

3) Skipping. Skipping varies from person to person but is basically a really short skid. Some people do it by popping a little skid and flicking the tail end out to one side a little other by picking the back wheel right of the ground to remove momentum in the drive train, others just do little forward skids. Each variation has a slightly different effect, both to the longevity of your tyre and also the amount of speed you loose. In my experience skipping comes first as you learn to skid as an accident. You try to skid but get a skip and then later once you have learnt to skid as a more effective way of braking and not burning through your tyre in a day. There isn't really much more to say about skipping, as I feel it is so personal. You just have to learn to skid first, and then experiment with doing different things.

I guess thats it really. My guide to stopping brakeless. I'm no expert, and I've probably got something wrong and its hardly a conclusive guide, but the intention is good, and it should give you some idea about ways of stopping a bike with just a fixed wheel drive train.

But by the sounds of it you aren't ready to go brakeless.
And you should probably get a lower gear. It will make learning easier.

hope that helps.[/serious answer]